I can tell you that A bigger, heavier, more rigid, more capable machine would be the way to go if you think this is a more than passing fancy. I like the Taig I started with, but I have spent enough keeping it going and modifying it to do more that I could have started with a bigger machine to begin with.
Which desert DsrtRat?
Six sides? I don't see any reason to cut from more than 4.
It looks like you are getting the basics, but you won't be able to just make one pass with any machine (certainly not with a Sherline or Taig), also you really need to think about how you are going to hold it and position it on the table after the first side. This is the headache I often see from designers who don't machine. They design to some ideal, but forget about practicality. Yeah, I do a little work in the machining field, but its my hobby. Not my job. The best designer I have worked with is a guy out of Jakarta, that emailed me and said, "I am designing this part for a guy in Oz. What things should I do to make it easier for you to machine?"